Abstract: In 2003～2005, the Monochamus alternatus infected Pinus thunbergii, P. massoniana and P. elliotii in pure and mixed forests were selected as attractants and dissected with one meter section manner, and five aggregation indices were used to analyze the spatial distribution patterns of M. alternatus and its natural enemy Dastarcus helophoroides. The results showed that M. alternatus and D. helophoroides had the horizontal distribution indices of diffused coefficient C＞1, diffused index I_δ＞1, Kuno index C_A＞0, clump intensity index I＞1, and swarm index I_w＞1 in the two stands, suggesting their aggregated horizontal distribution patterns, and except D. helophoroides on the P. massoniana in mixed forest appeared assemble vertical distribution, these two insects all had an even vertical distribution, with their C＜1, I_δ＜1, C_A＜0, I_w＜1, and I＜0. The spatial distribution patterns of M. alternatus and D. helophoroides were consistent, and the latter was spatially following the former.

Key words: Pinus elliottii, Multi benefit, Management pattern, Management density